CO-199 Denial Code: Revenue and Procedure Code Mismatch
The official definition
“Revenue code and Procedure code do not match”
That is the verbatim definition of CARC 199 from the X12 Claim Adjustment Reason Code set, the standardized codes every insurer uses on EOBs and remittance advices. The letters in front of the number are the group code. CO: Contractual Obligation: an adjustment between the provider and the insurer. An in-network provider should not bill you for CO amounts.
What it means in plain English
Two codes on the claim disagree with each other: the revenue code (which department or service category the hospital billed under) doesn't match the procedure code (what was actually done). This is a clerical inconsistency in the provider's billing, and it says nothing about your coverage or your care.
What to check on your EOB
- Whether you're being billed for the denied line. You shouldn't be; this is a provider coding error.
- Whether the claim was corrected and resubmitted; ask the billing office for the resubmission date.
What to do next
- Call the provider's billing office and ask them to reconcile the revenue code and procedure code, then resubmit.
- Follow up in 30 days. Corrected resubmissions resolve this denial at a very high rate.
Who's responsible
Provider. Most denials carry a clear owner. Knowing whether the fix belongs to you, your doctor, or the billing office is half the battle. If it's the provider's error, you should not be paying for it.
Want the fundamentals first? Start with how to read an EOB and the 7 most common billing errors. This page is general information about standardized denial codes, not legal or medical advice.
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